4.4.26: Static Linux Builds, Memory-Aware Batching & Cross-Compilation Fixes

This release includes critical build system improvements and enhanced batching capabilities for more predictable resource usage.

### Cross-Compilation & Static Builds
- Fixed cross-compilation for Linux by introducing architecture-specific `CGO_CFLAGS` (x86_64-linux-gnu and aarch64-linux-gnu), ensuring correct header resolution during static linking.
- Enabled fully static Linux binaries using musl, producing self-contained executables with no external runtime dependencies.

### Memory-Aware Batching (New Feature)
- Added `--batch-mem` CLI option to control batching based on estimated memory usage (e.g., 128K, 64M, 1G), in addition to size-based limits.
- Introduced configurable min/max batch sizes and memory thresholds, with conservative memory estimation per sequence to avoid over-allocation.
- Implemented intelligent flushing logic that triggers when *either* byte or record count limits are exceeded, ensuring predictable memory behavior.
- Improved garbage collection after large batch discards to reduce memory pressure during large-scale processing.

### Build & Toolchain Improvements
- Updated Go toolchain to 1.26.1 and bumped key dependencies (e.g., golang.org/x/net v0.38.0).
- Enhanced build error reporting: logs are now displayed before cleanup on failure.
- Fixed Makefile quoting for `LDFLAGS` containing spaces.
- Updated install script to properly configure GOROOT, GOPATH, and GOTOOLCHAIN, with added progress feedback for downloads.

All batching behavior is backward-compatible and uses sensible defaults (128 MB memory, min: 1 record, max: 2000 records) to ensure smooth upgrades.

version.txt

@@ -1 +1 @@
-4.4.25
+4.4.26